Method of improving ground and apparatus used therefor

摘要

A method of improving water retention characteristics of soil by using water absorption polymer, including the steps of forming a water impermeable layer in a subsurface layer of the ground, and providing a water absorption polymer layer in an upper region of the water impermeable layer. The method is executed by an apparatus for forming a water impermeable layer in a subsurface layer of the ground, the apparatus also being used to mix water absorption polymer in the soil in an upper region of the water impermeable layer, by an injecting apparatus having a drilling function.